CWE-300: Channel Accessible by Non-Endpoint

CWE-300: Channel Accessible by Non-Endpoint is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product does not adequately verify the identity of actors at both ends of a communication channel, or does not adequately ensure the integrity of the channel, in a way that allows the channel to be accessed or influenced by an actor that is not an endpoint. In order to establish secure communication between two parties, it is often important to adequately verify the identity of entities at each end of the communication channel. Inadequate or inconsistent verification may result in insufficient or incorrect identification of either communicating entity. This can have negative consequences such as misplaced trust in the entity at the other end of the channel. An attacker can leverage this by interposing between the communicating entities and masquerading as the original entity. In the absence of sufficient verification of identity, such an attacker can eavesdrop and potentially modify the communication between the original entities.

If exploited, CWE-300 (Channel Accessible by Non-Endpoint) it can compromise Confidentiality, Integrity and Access Control, leading to outcomes such as Read Application Data, Modify Application Data and Gain Privileges or Assume Identity.

Recommended mitigations for CWE-300 include: Always fully authenticate both ends of any communications channel. Adhere to the principle of complete mediation. A certificate binds an identity to a cryptographic key to authenticate a communicating party. Often, the certificate takes the encrypted form of the hash of the identity of the subject, the public key, and information such as time of issue or expiration using the issuer's private key. The certificate can be validated by deciphering the certificate with the issuer's public key. See also X.509 certificate signature chains and the PGP certification structure.

CWE-300 can be detected using Automated Dynamic Analysis and Automated Static Analysis. Combining automated tooling with manual review typically yields the best coverage.

CWE-300 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

MITRE documents real CVEs mapped to CWE-300, including CVE-2014-1266. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.

A CWE (Common Weakness Enumeration) like CWE-300 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.